path: root/gdb/testsuite/gdb.base/shlib-unload.exp

# Copyright 2024-2025 Free Software Foundation, Inc.

# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# Tests for GDB's handling of a shared library being unloaded via a
# call to dlclose.  See the individual test_* procs for a description
# of each test.

standard_testfile .c -lib.c

# One of the tests uses this Python file.  The test_* proc checks that
# GDB supports Python tests.  Some of the other procs don't use this
# Python file.
set pyfile [gdb_remote_download host ${srcdir}/${subdir}/${testfile}.py]

# Build the library and copy it to the target.
set libname ${testfile}-lib
set libfile [standard_output_file $libname]
if { [build_executable "build shlib" $libfile $srcfile2 {debug shlib}] == -1} {
    return
}
set libfile_on_target [gdb_download_shlib $libfile]

# Build the executable.
set opts [list debug shlib_load additional_flags=-DSHLIB_NAME=\"${libname}\"]
if { [build_executable "build exec" $binfile $srcfile $opts] == -1} {
    return
}

# The line number of the dlclose call.
set bp_line [gdb_get_line_number "Break here" $srcfile]

# If the target is remote, then the library name in the bp_disabled_re
# below will have a 'target:' prefix.
if {[is_remote target]} {
    set target_prefix_re "target:"
} else {
    set target_prefix_re ""
}

# The line emitted when GDB disables breakpoints after unloading a
# shared library.
set bp_disabled_re "warning: Temporarily disabling breakpoints for unloaded shared library \"$target_prefix_re[string_to_regexp $::libfile_on_target]\""

# The complete regexp for when GDB stops on the line after BP_LINE,
# assuming that GDB has disabled some breakpoints.
set stop_after_bp_re [multi_line \
			  "^$::bp_disabled_re" \
			  "[expr $::bp_line + 1]\\s+assert \\(res == 0\\);"]

# Checking that a breakpoint with multiple locations in a shared
# library only triggers a single breakpoint modified event from
# disable_breakpoints_in_unloaded_shlib when the shared library is
# unloaded.
proc_with_prefix test_bp_modified_events {} {
    if { ![allow_python_tests] } {
	unsupported "python support needed"
	return
    }

    clean_restart $::binfile

    if {![runto_main]} {
	return
    }

    # If the debug information doesn't allow GDB to identify inline
    # functions then this test isn't going to work.
    get_debug_format
    if { [skip_inline_frame_tests] } {
	unsupported "skipping inline frame tests"
	return
    }

    gdb_breakpoint $::srcfile:$::bp_line
    gdb_continue_to_breakpoint "stop before dlclose"

    gdb_breakpoint inline_func
    set bp_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
		    "get b/p number"]

    gdb_test_no_output "source $::pyfile" "import python scripts"

    gdb_test "next" $::stop_after_bp_re

    # The breakpoint should have been modified once when some of its
    # locations are made pending after the shared library is unloaded.
    gdb_test_multiple "python print(bp_modified_counts\[$bp_num\])" "" {
	-re -wrap "^1" {
	    pass $gdb_test_name
	}
	-re -wrap "^2" {
	    # A second event occurs when the pending breakpoint is
	    # incorrectly deleted.
	    kfail gdb/32404 $gdb_test_name
	}
	-re -wrap "^$::decimal" {
	    fail $gdb_test_name
	}
    }
}

# Check that GDB disables dprintf breakpoints within a shared library
# when the shared library is unloaded.
proc_with_prefix test_dprintf_after_unload {} {
    clean_restart $::binfile

    if {![runto_main]} {
	return
    }

    gdb_breakpoint $::srcfile:$::bp_line
    gdb_continue_to_breakpoint "stop before dlclose"

    # Setup a dprintf within the shared library.
    gdb_test "dprintf foo,\"In foo\""
    set bp_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
		    "get b/p number"]

    # Unload the shared library, GDB should disable our b/p.
    gdb_test "next" $::stop_after_bp_re

    # Check that our b/p is now showing as disabled.
    gdb_test "info breakpoints $bp_num" \
	[multi_line \
	     "^Num\\s+Type\\s+Disp\\s+Enb\\s+Address\\s+What" \
	     "$bp_num\\s+dprintf\\s+keep\\s+y\\s+<PENDING>\\s+foo" \
	     "\\s+printf \"In foo\""]
}

# Create a dprintf breakpoint in a shared library.  Restart the
# inferior.  We should not get an error about re-setting the dprintf
# breakpoint.
proc_with_prefix test_dprintf_with_rerun {} {
    clean_restart $::binfile

    if {![runto_main]} {
	return
    }

    gdb_breakpoint $::srcfile:$::bp_line
    gdb_continue_to_breakpoint "stop before dlclose"

    # Setup a dprintf within the shared library.
    gdb_test "dprintf foo,\"In foo\""
    set bp_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
		    "get b/p number"]

    # Check that the dprintf b/p is initially not pending.
    gdb_test "info breakpoints $bp_num" \
	[multi_line \
	     "^Num\\s+Type\\s+Disp\\s+Enb\\s+Address\\s+What" \
	     "$bp_num\\s+dprintf\\s+keep\\s+y\\s+$::hex\\s+in foo at \[^\r\n\]+" \
	     "\\s+printf \"In foo\""] \
	"dprintf is non-pending before restart"

    # Restart the inferior.
    gdb_run_cmd

    # The inferior will stop at the initial 'main' breakpoint.  This
    # is at a location before any of the shlibs have been loaded.
    set saw_bp_reset_error false
    set saw_bp_disable_warning false
    gdb_test_multiple "" "stop before shlib are reloaded" {
	-re "warning: Temporarily disabling breakpoints for unloaded shared library \"\[^\r\n\]+/$::libname\"\r\n" {
	    set saw_bp_disable_warning true
	    exp_continue
	}

	-re "Error in re-setting breakpoint $bp_num: \[^\r\n\]+" {
	    set saw_bp_reset_error true
	    exp_continue
	}

	-re "Breakpoint $::decimal, main \\(\\) at \[^\r\n\]+\r\n$::decimal\\s+\[^\r\n\]+\r\n$::gdb_prompt $" {
	    gdb_assert { !$saw_bp_reset_error && !$saw_bp_disable_warning } $gdb_test_name
	}
    }

    # Check that the dprintf b/p is still enabled, but marked pending
    # before the shlib are loaded.
    gdb_test "info breakpoints $bp_num" \
	[multi_line \
	     "^Num\\s+Type\\s+Disp\\s+Enb\\s+Address\\s+What" \
	     "$bp_num\\s+dprintf\\s+keep\\s+y\\s+<PENDING>\\s+foo" \
	     "\\s+printf \"In foo\""] \
	"dprintf is pending before shlib reload"

    set saw_in_foo_output false
    gdb_test_multiple "continue" "stop after libraries are reloaded" {
	-re "^continue\r\n" {
	    exp_continue
	}
	-re "^Continuing\\.\r\n" {
	    exp_continue
	}
	-re "^In foo\r\n" {
	    set saw_in_foo_output true
	    exp_continue
	}
	-re "^Breakpoint $::decimal, main \\(\\) at .* Break here\\.  \\*/\r\n$::gdb_prompt $" {
	    gdb_assert { $saw_in_foo_output } $gdb_test_name
	}
    }

    # Check that the dprintf b/p is still enabled, but is now, no
    # longer pending.
    gdb_test "info breakpoints $bp_num" \
	[multi_line \
	     "^Num\\s+Type\\s+Disp\\s+Enb\\s+Address\\s+What" \
	     "$bp_num\\s+dprintf\\s+keep\\s+y\\s+$::hex\\s+in foo at \[^\r\n\]+" \
	     "\\s+breakpoint already hit 1 time" \
	     "\\s+printf \"In foo\""] \
	"dprintf is non-pending after restart"
}

# Check that we see breakpoint modified events (where appropriate)
# when the 'nosharedlibrary' command is used to unload all shared
# libraries.
#
# Also check that the 'nosharedlibrary' doesn't trigger a warning
# about shared library breakpoints being disabled.
proc_with_prefix test_silent_nosharedlib {} {
    if { ![allow_python_tests] } {
	unsupported "python support needed"
	return
    }

    foreach_with_prefix type { breakpoint dprintf } {
	clean_restart $::binfile

	if {![runto_main]} {
	    return
	}

	gdb_breakpoint $::srcfile:$::bp_line
	gdb_continue_to_breakpoint "stop before dlclose"

	# Setup a dprintf or breakpoint in the shared library.
	if { $type eq "breakpoint" } {
	    gdb_test "break foo"
	} else {
	    gdb_test "dprintf foo,\"In foo\""
	}

	# Record the number of the b/p (or dprintf) we just inserted.
	set bp_num [get_integer_valueof "\$bpnum" "*UNKNOWN*" \
			"get b/p number"]

	# Load Python library to track b/p modifications.
	gdb_test_no_output "source $::pyfile" "import python scripts"

	# Initialise the b/p modified hash.  Currently dprintf style
	# breakpoints are not visible from Python, so the modification
	# count will remain unchanged in that case.
	gdb_test_no_output "python bp_modified_counts\[$bp_num\] = 0"

	# Discard symbols from all loaded shared libraries.
	gdb_test_no_output "nosharedlibrary"

	# Check that our b/p is now showing as disabled.
	if { $type eq "breakpoint" } {
	    set re \
		[list "$bp_num\\s+breakpoint\\s+keep\\s+y\\s+<PENDING>\\s+foo"]
	    set count 1
	} else {
	    set re \
		[list \
		     "$bp_num\\s+dprintf\\s+keep\\s+y\\s+<PENDING>\\s+foo" \
		     "\\s+printf \"In foo\""]
	    set count 0
	}

	gdb_test "info breakpoints $bp_num" \
	    [multi_line "^Num\\s+Type\\s+Disp\\s+Enb\\s+Address\\s+What" \
		 {*}$re]

	# Check we've seen the expected number of breakpoint modified
	# events.  Currently dprintf breakpoints are not visible from
	# Python, so we will not see an event in that case.
	gdb_test "python print(bp_modified_counts\[$bp_num\])" "^$count"
    }
}

test_bp_modified_events
test_dprintf_after_unload
test_dprintf_with_rerun
test_silent_nosharedlib